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Gasdermin D (GSDMD) is the key executor of pyroptotic cell death. Recent studies suggest that GSDMD-mediated pyroptosis is involved in atherosclerotic plaque destabilization. We report that cleaved GSDMD is expressed in macrophage- and smooth muscle cell-rich areas of human plaques. To determine the effects of GSDMD deficiency on atherogenesis, <i>ApoE^−/− Gsdmd</i>^−/− (<i>n</i> = 16) and <i>ApoE^−/−</i><i>Gsdmd^+/+</i> (<i>n</i> = 18) mice were fed a western-type diet for 16 weeks. Plaque initiation and formation of stable proximal aortic plaques were not altered. However, plaques in the brachiocephalic artery (representing more advanced lesions compared to aortic plaques) of <i>ApoE^−/− Gsdmd^−/−</i> mice were significantly smaller (115 ± 18 vs. 186 ± 16 × 10³ µm², <i>p</i> = 0.006) and showed features of increased stability, such as decreased necrotic core area (19 ± 4 vs. 37 ± 7 × 10³ µm², <i>p</i> = 0.03) and increased αSMA/MAC3 ratio (1.6 ± 0.3 vs. 0.7 ± 0.1, <i>p</i> = 0.01), which was also observed in proximal aortic plaques. Interestingly, a significant increase in TUNEL positive cells was observed in brachiocephalic artery plaques from <i>ApoE^−/− Gsdmd^−/−</i> mice (141 ± 25 vs. 62 ± 8 cells/mm², <i>p</i> = 0.005), indicating a switch to apoptosis. This switch from pyroptosis to apoptosis was also observed in vitro in <i>Gsdmd^−/−</i> macrophages. In conclusion, targeting GSDMD appears to be a promising approach for limiting the transition to an inflammatory, vulnerable plaque phenotype.